Pose tracking control of an omni-directional wheel-type robot for a heavy-water nuclear reactor

In this paper, a PID controller is designed to solve position and orientation tracking control of a robot for a heavy-water nuclear reactor when the robot keeps track of a circular reference trajectory to show mobility for small turning radius. The four-wheel-drive robot is designed to have two omni-directional rear wheels for mobility and the tool center is located just above of the geometric center of the mobile base for stability. The complex nonlinear system dynamics of the omni-directional wheel-type robot is modeled with the RecurDyn. Using this dynamic model, a linear control theory based on a two wheel differential-drive robot is applied to design the robot controllers. The control strategy needs not only to keep track of a trajectory of a small radius, but also to locate the tools center to the proper position, with only position and orientation measurement. The co-simulation between RecurDyn and CoLink is built with the derived control strategy and some simulated results are presented.